This invention relates to lightweight, thermoplastic, vehicle headliners having at least one integrally-formed, energy-absorbing, head-impact mechanism and injection molding methods for making same.
Modern-day vehicle headliners must meet a number of requirements. Not only must headliners by lightweight and cost competitive with alternative headliners, but they must be recyclable, have good acoustic properties and meet head-impact requirements.
U.S. Pat. No. 4,119,749 discloses a headliner formed from foam panels shaped in a mold and is impregnated within the elastomer.
U.S. Pat. No. 4,131,702 discloses molding of laminated foam panels by heat for producing a headliner.
U.S. Pat. No. 4,172,918 discloses foamed plastic in a decorative cover that is heated and bonded.
U.S. Pat. No. 4,478,660 discloses a decorative cover and a carrier that are connected by a foam with heat and pressure in a mold.
U.S. Pat. No. 4,600,621 discloses a foam that is covered with a decorative fabric.
U.S. Pat. Nos. 5,007,976 and 5,082,716 disclose methods of making headliners in a mold using decorative fabric and a foam joined by an adhesive.
U.S. Pat. No. 5,089,328 discloses a method of making a panel having a foam-backed cover including layers that are bonded together by heat in a mold.
U.S. Pat. No. 5,660,908 discloses a vehicle headliner including reverse ribs for support.
U.S. Pat. No. 5,622,402 discloses an interior structural panel for a vehicle including a thermoplastic air duct.
U.S. Pat. No. 5,575,500 discloses a structural upper body member for a vehicle including a vertical element having an outer and an inner member forming a cavity therebetween.
U.S. Pat. No. 5,306,068 discloses a door including a plurality of integral foam resin tubes.
U.S. Pat. No. 4,413,856 discloses a rigid bumper mounted to a vehicle by cellular spring brackets.
U.S. Pat. No. 3,444,034 discloses a synthetic structural panel having integral interconnected portions.
U.S. Pat. No. 5,482,669 discloses a method and apparatus for creating gas-assisted injection molded structures.
U.S. Pat. No. 5,574,087 discloses a molded-resin, protective strip for vehicles.
U.S. Pat. No. 5,900,199 discloses a grille guard comprising a plastic-molded, pipe-like structure.
U.S. Pat. No. 4,995,659 discloses apparatus including tubular air sheets that cover the majority of a vehicle for reducing shock.
U.S. Pat. No. 3,853,349 discloses a vehicle body including a large number of cylindrical cavities.
U.S. Pat. No. 5,429,412 discloses a plastic fascia for attachment to a fender panel.
An object of the present invention is to provide a lightweight, thermoplastic, vehicle headliner having at least one integrally-formed, energy-absorbing, head-impact mechanism and an injection molding method for making same wherein the headliner is relatively inexpensive and light, is recyclable, has good acoustic properties and meets head-impact requirements.
Another object of the present invention is to provide a lightweight, thermoplastic, vehicle headliner having at least one integrally-formed, energy-absorbing, head-impact mechanism and an injection molding method for making same wherein the headliner is dimensionally stable, will hold its shape while spanning a passenger compartment, and is capable of meeting close tolerances, even when exposed to high humidity and elevated temperatures such as experienced by vehicles in tropical and hot desert climates.
Yet another object of the present invention is to provide a lightweight, thermoplastic, vehicle headliner having at least one integrally-formed, energy-absorbing, head-impact mechanism and an injection molding method for making same wherein the headliner is readily handled either manually or by automated equipment and inserted and held while being fastened to the interior of the occupant compartment of the vehicle.
Yet still another object of the present invention is to provide a lightweight, thermoplastic, vehicle headliner having at least one integrally-formed, energy-absorbing, head-impact mechanism and an injection molding method for making same wherein the headliner can be manufactured within a single injection mold.
In carrying out the above objects and other objects of the present invention, a lightweight, thermoplastic headliner for use in a vehicle having a roof is provided. The headliner includes a stiff, self-supporting, thermoplastic sheet adapted to be mounted adjacent the roof so as to underlie the roof and shield the roof from view. The sheet has an upper surface and a lower surface. The headliner also includes at least one energy-absorbing, head-impact mechanism formed on the sheet for absorbing energy of an impact with the headliner by a passenger of the vehicle.
In one embodiment, the at least one head-impact mechanism includes a plurality of spaced-apart, energy-absorbing, thermoplastic structures which are connected to and extend upwardly from the upper surface of the thermoplastic sheet. The thermoplastic structures may be ribs which are permanently deformable by the roof for absorbing energy of the impact.
The at least one head-impact mechanism may include a fabric or other material having a foam backing bonded to the lower surface of the thermoplastic sheet to create a cosmetically-acceptable appearance for the headliner. The fabric and its foam backing are compressed by a passenger of the vehicle to absorb energy of the impact.
In another embodiment, the at least one head-impact mechanism includes a series of tubular voids formed in the thermoplastic sheet. The voids are compressible for absorbing energy of the impact.
Preferably, the headliner further includes at least one attachment mechanism integrally formed with the thermoplastic sheet. The at least one attachment mechanism may be a hollow, plastic, grab handle.
The at least one attachment mechanism may provide an attachment location for securing a sun visor, a mirror, an overhead console, a coat hanger, or a lamp to the headliner.
The thermoplastic of the sheet may be thermoplastic polyolefin (TPO) or polypropylene or ABS.
The at least one attachment mechanism may include a plurality of spaced, apertured structures for receiving and retaining electrical wires therein.
The at least one attachment mechanism may include a pair of apertured window frames adapted to be received and retained within corresponding openings in the roof of the vehicle.
Further in carrying out the above objects and other objects of the present invention, an injection molding method for making a lightweight, thermoplastic, vehicle headliner having at least one integrally-formed, energy-absorbing, head-impact mechanism is provided. The method includes providing an injection mold having first and second mold halves, closing the mold so that the first and second mold halves define a mold cavity, and injecting molten, thermoplastic resin into the mold cavity to form a headliner including a stiff, self-supporting, thermoplastic sheet and a plurality of spaced-apart, energy-absorbing structures. The method further includes cooling the headliner beneath the softening point of the molten resin and opening the mold and removing the headliner. The energy-absorbing structures may be ribs.
Still further in carrying out the above objects and other objects of the present invention, a second injection molding method for making a lightweight, thermoplastic, vehicle headliner having at least one integrally-formed, energy-absorbing, head-impact mechanism is provided. The method includes providing an injection mold having first and second mold halves, closing the mold so that first and second mold halves define a mold cavity, and injecting molten, thermoplastic resin into the mold cavity. The method further includes communicating a charge of pressurized fluid into the mold cavity to distribute the molten resin over the interior surfaces of the mold and to form a series of tubular voids in the molten resin. The method still further includes containing the fluid under pressure until a headliner including a stiff, self-supporting, thermoplastic sheet and a series of tubular voids formed therein have set up. Finally, the method includes cooling the headliner beneath the softening point of the molten resin, and opening the mold and removing the headliner.
Yet still further in carrying out the above objects and other objects of the present invention, a third injection molding method for making a lightweight, thermoplastic, vehicle headliner having at least one integrally-formed, energy-absorbing, head-impact mechanism is provided. The method includes providing an injection mold having first and second mold halves, placing a fabric or other material having a foam backing between the first and second mold halves, and closing the mold so that the first and second mold halves define a mold cavity with the fabric or other material in the mold cavity. The method also includes injecting molten, thermoplastic resin into the mold cavity to generate a stiff, self-supporting, thermoplastic sheet. The generation of the sheet creates sufficient pressure and heat to bond the sheet to the foam to form a headliner. The method further includes cooling the headliner beneath the softening point of the molten resin, and opening the mold and removing the headliner.